One of wafer process steps for manufacturing a semiconductor apparatus is an SOG (spin on glass) film formation step (e.g., see PTL 1). An SOG film is mainly used to reduce height differences of inter-layer insulating films formed on a wiring or embed inter-wire grooves. The SOG film has viscosity, and is applied while rotating a silicon wafer and formed by further rotating the silicon wafer after the application to adjust the film thickness. For quality management of the wafer process step, it is necessary to measure the film thickness of the SOG film.
The film thickness measurement of the SOG film is performed by calculating different light reflection factors of the wiring and the SOG film and measuring the film thickness of the SOG film on the wiring. A film thickness measurement wiring pattern is normally placed not in a chip but on a dicing line. A dicing line width needs to be kept to a minimum necessary for increasing the number of chips taken per wafer and increasing productivity.